olmsted



(No Mbdel.) 2 Sheets-Sheet 1.

J. OLMSTED.

DYNAMO ELECTRIC MACHINE.

Patented Aug. 19, 1884.

(No Model.) 2 Sheets-Sheet 2.

J. OLMSTED.

DYNAMO ELECTRIC MACHINE.

No. 303,744., Patented Aug. 19, 1884;.

N. PETERS. Phnloiflhognpher, Waslnup,

THE OLMSTED ELECTRIC LIGHT AND POl/VER COMPANY, OFNEV YORK.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 303,744,

dated August 19,1884.

Application filed November 24. 1883. (No model.)

To all whom it may concern.-

Be it know u that I, JOSEPH OLMSTED, a citizen of the United States, and a resident of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Armatures for Dynamo- Electric Machines, of which the following is a specification.

My invention relates to armatures for dyio namo-electric or magneto-electric machines, and more especially to the construction of the cylindrical carrier or frame upon which the coils of cylinder-armatures are wound.

The obj eet of my invention is to so construct the carrier as to permit the circulation of air through and between the coils, thus preventing injurious heating of said coils, and to also so form the portion of the carrier that is made of iron as to prevent the formation of so-called 2o Foucault currents.

To these ends my invention consists of certain novel details of construction and combinations of parts, that will be herein described in connection with the accompanying drawings, and then pointed out in the claims.

In the accompanying drawings, Figure I is a longitudinal section of an armature-carrier embodying my invention with the armaturecoils removed. Fig. II is a transverse section 0 of the carrier at right angles to its axis. Fig. III is a top View of a portion of the armature, showing a portion of an armature-coil. v

In the various figures, A-indicates the armatureshaft, made hollow, and open at its 5 ends to allow ingress of air. This shaft is to be mounted in journals in the usual Way, and is provided at its central portion with perforations, (indicated at ]L,) that allow the air taken in at theends to pass out and through the ar- 0 mature-coils. SecuredtotheshaftAare disks, rings, or supports B, made of any desired materialsuch as iron or brass-upon which disks are secured a series of bars or strips, 0, of wood or other insulating material, placed parallel to the shaft and separated from one another by narrow spaces, as indicated in Figs. 2 and 3, so as to allow air to escape from the interior of the armature. The wooden strips as thus arranged and supported form in outline a cylinder, upon which are wound circumo ferentially coils of iron wire I), separated from one another by wooden pins F, which latter serve, also,'to divide or space the armaturecoils, one of which coils is indicated at L, Figs. 2 and 3. The iron wire D forms the iron cylinder upon which the armature-coils are wound in any of the usual ways. To prevent the circulation of Foucault currents, I insert midway between the outer and inner layers of each set of coils D a strip of insulating mate 6 rial (indicated at E) that extends longitudinally from one side of the coil half or approximately half way to the other side of the coil. I find by actual test that by extending the strip but a portion of the way through the coil 6 I avoid the formation of Foucault currents in the body of the coil to a much greater extent thanif the strip extends clear through the coil.

The insulation E may be arranged to partially divide the coils either longitudinally in a plane parallel to the armatureaxis or in a planetransverse thereto. The dividing of the iron coils into sections by the insulatingpins F'also tends to prevent the formation of the induced currents. The pins F alternate, as 7 5 shown-that is, those in the same cireuml'en ential line are placed on every other strip (J, and in neighboring circumferential lines break. joint or alternate. The purpose of this is to leave openings between the armature-coils for So the circulation of the air.

What I claim as my invention isl. The combination, with the hollow perforated armature-shaft, of two or more disks or supports secured thereto, and a series of longitudinal strips or bars of wood or other insulating material separated from one another by free-air spaces, and placed parallel to the armature-shaft, as described.

2. The combination of the hollow perfo- 0 rated armature-shaft, the two or more disks or supports, a series of bars of wood or other insulating material separated from one another and forming in outline a cylinder, and coils of iron wire wound circumferentially upon said 9 5 cylinder and separated by free-air spaces.

3. The combination, with the series of separated bars or strips 0, of the pins F, the cir- 5. The conibinulion ol" the hollow perfo- 10 rated ulrniul'ui'e-shel't, the disks B, the strips C, separated from one another, the coils 1), zuul the pins l us and for the purpose described.

Signed all New York, in the eouulay 01. New York and Slate ofNew York, this 15th (lily of November, A. l). 188; 

